235265283...

Short SAE blurb describing Z06 LT6 intake manifold:
The I/O Buffer Information Specification (IBIS) Open Forum Releases the IBIS Version 7.1 Specification (sae.org)

JMB

Thanks for sharing

GrandSport 2017

Gee, I would have thought they would have actually explained what was going on dynamically with the entire induction system, being an SAE write up.

It would be nice to see all the math involved. Maybe GM will allow someone to disclose this technical information for all you techies some day.

235265283...

IMO, the basic principles colorfully referred to in this blurb have been known (and applied to various extents) for a long time. For example, a relatively easy-to-read book with some math (but no CFD stuff) that explains these principles is; Scientific Design of Exhaust and Intake Systems, by Philip Smith, Robert Bentley 1962

GrandSport 2017

Yes much of it has been known and used for many decades.
An even better book that goes into all the detail was written by Gordon Blair in 1999. "The Design and Simulation of 4 Stroke engines". If you are an SAE member you can get a discount on it.

The real trick isn't the trumpets that dictate the single cylinder induction frequency, that is pretty straight forward, however they are are canted to reduce cross talk but the controlling of the multi cylinder induction frequency is where it gets really interesting. Maybe they will allow the sharing of the CFD data of the plenums and valving some day.

vndkshn

Kinda disappointed in this statement:
"Let the record show that the LT6 is the most powerful naturally aspirated V8 ever produced."

Doesn't GM have an even more powerful V8 crate option? And there are some other aftermarket options as well. Maybe semantics, but "the LT6 is the most powerful naturally aspirated V8 ever put in a factory production car" seems more accurate.

Yes, SAE doesn't care about aftermarket, but they are known to be pretty particular about accuracy so I think my comment applies.

Katech_Mike

It's an accurate statement. They are referring to horsepower per cubic inch. The LT6 is 2.01hp/ci where as the 632 is 1.58hp/ci.

vndkshn

So STILL not an accurate statement. If you are going to say something, say it clearly, state "highest horsepower per cubic inch/liter in a factory production engine".

Again, my point is the statement as made is NOT accurate because they left the details out.

If you want to assume they meant something else (which they probably did), that's on you. But I hold SAE to a higher standard than CNN/MSNBC/Foxnews/etc.

vndkshn

@Katech_Mike
BTW, your example seems to be wrong.

5.5L engine in the Z06. Assuming it is exactly 5.5L, that's 335.631ci. Take the 670 and divide by 335.631 I get 1.99hp/ci. So, close enough to your 2.01.
BUT
458's engine is 4.5L, 562hp. Take 562 and divide by 247.607 (actual cc is 247.4, but the bigger number actually lowers the hp/ci) and you get 2.269hp/ci.

So I'm not following how the LT6 is the highest HP per cubic inch NA V8.... I think they really meant the highest output NA V8 and left out the "factory production car engine" part.

George_L

From the Chevy Z06 Website.

GrandSport 2017

So who made a production N/A V8 that was higher hp?
Either per liter or out right?

I'm all ears. Just asking.

OnPoint

Chevrolet does.

But not in a production car. Which I think is the semantics snag people are tripping over.

GrandSport 2017

Yea well the production part was pretty well implied, I mean it was said at the original release of the engine in the car, so.... I guess its winter and people need to debate over something... next big news is still a few months away.

OnPoint

I agree. But, like you say, it's winter and . . . .

2cnd Chance

E-Ray or Grand Sport?

descartesfool

I was disappointed when I got the newsletter from SAE with that article, as it revealed nothing new about the induction system than what had been published/disclosed before. As said above, no math, no numbers, no charts.

GrandSport 2017

Magic 8 Ball says...
/ cant \
answer that
\ now /

2cnd Chance

Understood.

RedLS6

Sherman's good at listing known surface facts, without providing any depth.

vndkshn

The article said "production engine", no mention about "production car". I'm really just picking on SAE here, they are usually known for being very precise (hey, its what they do) when they say something. Do I know what they mean? Of course. Does it still disappoint? I surely hope that SAE isn't going to drop into the shoddy traits of mainstream media.